1. Field of the Invention
The present invention relates to an improved vehicle leveling system of the type in which pneumatic pressure is fed to and discharged from air chambers attached to hydraulic shock absorbers so that the vehicle height may be selectively adjusted to a higher or lower level.
2. Description of Relevant Art
In known pneumatic vehicle leveling systems for selectively adjusting vehicle height, when the pneumatic pressure is fed to or discharged from the air chambers of the hydraulic shock absorbers to thereby adjust the vehicle height, the compressed air is fed from an air source such as a compressor or an air pump through a pipe, a change-over valve and other pneumatic circuitry components, if necessary, to a pair of right and left front shock absorbers and a pair of right and left rear shock absorbers, so as to thus raise the height of the vehicle. On the other hand, when it is desired to lower the vehicle height, the compressed air is discharged from the pipe through a discharge valve and other pneumatic circuitry. However, if for some unusual reason the pneumatic pressure is imbalanced between the shock absorbers of the front and rear wheels, a problem arises in that the vehicle height at the front wheel side is increased whereas the vehicle height at the rear wheel side is decreased, or that the vehicle height at the front wheel side becomes lower than that at the rear wheel side.
The present invention provides an air-leveling system which effectively overcomes the aforesaid problem attendant known vehicle air-leveling systems.